Libguestfs - Aug 2016 - [PATCH] New API: aug_transform

Expose the aug_transform API through the library, so it's possible to
add/remove Augeas transformations to handle files in custom places using
existing lenses.
---
 daemon/augeas.c      | 21 +++++++++++++++++++++
 generator/actions.ml | 12 ++++++++++++
 gobject/Makefile.inc |  2 ++
 src/MAX_PROC_NR      |  2 +-
 4 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/daemon/augeas.c b/daemon/augeas.c
index 14cc0cf..5adc959 100644
--- a/daemon/augeas.c
+++ b/daemon/augeas.c
@@ -491,3 +491,24 @@ do_aug_label (const char *augpath)
 
   return ret;                   /* caller frees */
 }
+
+/* Takes optional arguments, consult optargs_bitmask. */
+int
+do_aug_transform (const char *lens, const char *file, int remove)
+{
+  int r;
+  int excl = 0; /* add by default */
+
+  NEED_AUG (-1);
+
+  if (optargs_bitmask & GUESTFS_AUG_TRANSFORM_REMOVE_BITMASK)
+    excl = remove;
+
+  r = aug_transform (aug, lens, file, excl);
+  if (r == -1) {
+    AUGEAS_ERROR ("aug_transform: %s: %s: %s", lens, file, excl ?
"excl" : "incl");
+    return -1;
+  }
+
+  return r;
+}
diff --git a/generator/actions.ml b/generator/actions.ml
index eccef00..aa26649 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -13205,6 +13205,18 @@ only the unallocated blocks will be extracted.
 This is useful to detect hidden data or to retrieve deleted files
 which data units have not been overwritten yet." };
 
+  { defaults with
+    name = "aug_transform"; added = (1, 35, 2);
+    style = RErr, [String "lens"; String "file"], [ OBool
"remove"];
+    proc_nr = Some 469;
+    shortdesc = "add/remove an Augeas lens transformation";
+    longdesc = "\
+Add an Augeas transformation for the specified C<lens> so it can
+handle C<file>.
+
+If C<remove> is true (C<false> by default), then the transformation
+is removed." };
+
 ]
 
 (* Non-API meta-commands available only in guestfish.
diff --git a/gobject/Makefile.inc b/gobject/Makefile.inc
index 7698c2a..149e4c6 100644
--- a/gobject/Makefile.inc
+++ b/gobject/Makefile.inc
@@ -53,6 +53,7 @@ guestfs_gobject_headers= \
   include/guestfs-gobject/optargs-add_drive.h \
   include/guestfs-gobject/optargs-add_drive_scratch.h \
   include/guestfs-gobject/optargs-add_libvirt_dom.h \
+  include/guestfs-gobject/optargs-aug_transform.h \
   include/guestfs-gobject/optargs-btrfs_filesystem_defragment.h \
   include/guestfs-gobject/optargs-btrfs_filesystem_resize.h \
   include/guestfs-gobject/optargs-btrfs_fsck.h \
@@ -143,6 +144,7 @@ guestfs_gobject_sources= \
   src/optargs-add_drive.c \
   src/optargs-add_drive_scratch.c \
   src/optargs-add_libvirt_dom.c \
+  src/optargs-aug_transform.c \
   src/optargs-btrfs_filesystem_defragment.c \
   src/optargs-btrfs_filesystem_resize.c \
   src/optargs-btrfs_fsck.c \
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 1023289..5ef9d24 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-468
+469
-- 
2.7.4

Add also /boot/efi/EFI/redhat/grub.conf as configuration of Grub 1;
since the "grub" lens of Augeas does not handle this path, add a
transformation so Augeas can parse it.
---
 v2v/convert_linux.ml | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/v2v/convert_linux.ml b/v2v/convert_linux.ml
index 9941750..2a53315 100644
--- a/v2v/convert_linux.ml
+++ b/v2v/convert_linux.ml
@@ -96,7 +96,11 @@ let rec convert ~keep_serial_console (g : G.guestfs) inspect
source rcaps      ] in
     let locations        match inspect.i_firmware with
-      | I_UEFI _ -> ("/boot/efi/EFI/redhat/grub.cfg", `Grub2) ::
locations
+      | I_UEFI _ ->
+        [
+          "/boot/efi/EFI/redhat/grub.cfg", `Grub2;
+          "/boot/efi/EFI/redhat/grub.conf", `Grub1;
+        ] @ locations
       | I_BIOS -> locations in
     try
       List.find (
@@ -111,6 +115,11 @@ let rec convert ~keep_serial_console (g : G.guestfs)
inspect source rcaps      match grub with
     | `Grub2 -> ""
     | `Grub1 ->
+      if grub_config = "/boot/efi/EFI/redhat/grub.conf" then (
+        g#aug_transform "grub"
"/boot/efi/EFI/redhat/grub.conf";
+        Linux.augeas_reload g;
+      );
+
       let mounts = g#inspect_get_mountpoints inspect.i_root in
       try
         List.find (
-- 
2.7.4

On Fri, Aug 19, 2016 at 04:25:42PM +0200, Pino Toscano
wrote:
> Add also /boot/efi/EFI/redhat/grub.conf as configuration of Grub 1;
> since the "grub" lens of Augeas does not handle this path, add a
> transformation so Augeas can parse it.
> ---
>  v2v/convert_linux.ml | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/v2v/convert_linux.ml b/v2v/convert_linux.ml
> index 9941750..2a53315 100644
> --- a/v2v/convert_linux.ml
> +++ b/v2v/convert_linux.ml
> @@ -96,7 +96,11 @@ let rec convert ~keep_serial_console (g : G.guestfs)
inspect source rcaps >      ] in
>      let locations >        match inspect.i_firmware with
> -      | I_UEFI _ -> ("/boot/efi/EFI/redhat/grub.cfg", `Grub2)
:: locations
> +      | I_UEFI _ ->
> +        [
> +          "/boot/efi/EFI/redhat/grub.cfg", `Grub2;
> +          "/boot/efi/EFI/redhat/grub.conf", `Grub1;
> +        ] @ locations
>        | I_BIOS -> locations in
>      try
>        List.find (
> @@ -111,6 +115,11 @@ let rec convert ~keep_serial_console (g : G.guestfs)
inspect source rcaps >      match grub with
>      | `Grub2 -> ""
>      | `Grub1 ->
> +      if grub_config = "/boot/efi/EFI/redhat/grub.conf" then (
> +        g#aug_transform "grub"
"/boot/efi/EFI/redhat/grub.conf";
> +        Linux.augeas_reload g;
> +      );
> +
>        let mounts = g#inspect_get_mountpoints inspect.i_root in
>        try
>          List.find (
ACK both.

You might need to adjust the augeas min version detection in
m4/guestfs_libraries.m4.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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